1 /**
2 * @file
3 */
4
5 /*
6 Copyright (C) 2002-2013 UFO: Alien Invasion.
7
8 This program is free software; you can redistribute it and/or
9 modify it under the terms of the GNU General Public License
10 as published by the Free Software Foundation; either version 2
11 of the License, or (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16
17 See the GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22
23 */
24
25 #include "common.h"
26
dbuffer(int reserve)27 dbuffer::dbuffer (int reserve) : _length(0)
28 {
29 _data.reserve(reserve);
30 }
31
dbuffer(const dbuffer & other)32 dbuffer::dbuffer (const dbuffer &other)
33 {
34 _data = other._data;
35 _length = other._length;
36 }
37
~dbuffer()38 dbuffer::~dbuffer ()
39 {
40 }
41
add(const char * data,size_t len)42 void dbuffer::add (const char* data, size_t len)
43 {
44 _data.insert(_data.begin() + _length, data, data + len);
45 _length += len;
46 }
47
48 /**
49 * @brief Read data from a dbuffer
50 * @param[out] data pointer to where the data should be copied
51 * @param[in] len maximum number of bytes to copy
52 * @return number of bytes copied
53 *
54 * @par
55 * Copies up to @c len bytes into @c data
56 *
57 * @par
58 * If the buffer does not contain at least @c len bytes, then as many
59 * bytes as are present will be copied.
60 */
get(char * data,size_t len) const61 size_t dbuffer::get (char* data, size_t len) const
62 {
63 if (len > _length) {
64 len = _length;
65 }
66 std::vector<char>::const_iterator copyEnd = _data.begin() + len;
67 std::copy(_data.begin(), copyEnd, data);
68
69 return len;
70 }
71
72 /**
73 * @brief Read data from a dbuffer
74 * @param[in] offset the offset in the source buffer where data should be copied from
75 * @param[out] data pointer to where the data should be copied
76 * @param[in] len maximum number of bytes to copy
77 * @return number of bytes copied
78 *
79 * @par
80 * Copies up to @c len bytes into @c data
81 *
82 * @par
83 * If the buffer does not contain at least @c len bytes after offset,
84 * then as many bytes as are present will be copied.
85 */
getAt(size_t offset,char * data,size_t len) const86 size_t dbuffer::getAt (size_t offset, char* data, size_t len) const
87 {
88 if (offset > _length)
89 return 0;
90
91 std::vector<char>::const_iterator copyBegin = _data.begin() + offset;
92 len = std::min(len, _length - offset);
93 std::vector<char>::const_iterator copyEnd = copyBegin + len;
94 std::copy(copyBegin, copyEnd, data);
95
96 return len;
97 }
98
99 /**
100 * @brief Deletes data from a dbuffer
101 * @param[in] len number of bytes to delete
102 * Deletes the given number of bytes from the start of the dbuffer
103 */
remove(size_t len)104 size_t dbuffer::remove (size_t len)
105 {
106 if (len <= 0) {
107 return 0;
108 }
109
110 if (len > _length) {
111 len = _length;
112 }
113 std::vector<char>::iterator eraseEnd = _data.begin() + len;
114 _data.erase(_data.begin(), eraseEnd);
115 _length -= len;
116 return len;
117 }
118
119 /**
120 * @brief Read and delete data from a dbuffer
121 * @param[out] data pointer to where the data should be copied
122 * @param[in] len maximum number of bytes to copy
123 * @return number of bytes copied
124 *
125 * @par
126 * Copies up to @c len bytes into @c data, and removes them from the dbuffer
127 *
128 * @par
129 * If the buffer does not contain at least @c len bytes, then as many
130 * bytes as are present will be copied.
131 *
132 * @par
133 * However many bytes are copied, exactly that many will be removed
134 * from the start of the dbuffer.
135 */
extract(char * data,size_t len)136 size_t dbuffer::extract (char* data, size_t len)
137 {
138 len = get(data, len);
139 remove(len);
140 return len;
141 }
142